This invention relates in general to conveyors for transporting packages from one location to another. In particular, this invention relates to an improved structure for supporting a top guide relative to a plenum in an air driven conveyor that allows the distance therebetween to be quickly and easily adjusted in order to readily accommodate articles of differing size.
Conveyors are well known devices that are commonly used to support and transport articles from one location to another, such as in production line situations. For example, a conveyor may be used to transport packages of a product from an upstream entry station, wherein the empty packages are introduced into the production line, to a midstream filling station, wherein the packages are filled with the product and sealed, and further to a downstream packaging station, wherein the sealed packages are packaged into larger shipping containers. Many conveyor structures are known in the art for accomplishing these basic support and transportation functions.
One known type of conveyor is an air driven conveyor. A typical air driven conveyor includes a plenum that includes an upper surface having a plurality of holes or other openings formed therethrough. The air driven conveyor further includes a fan or other apparatus for causing air to flow into the interior of the plenum. When the air flow apparatus is turned on, the pressure of the air contained within the plenum increases above the ambient air pressure outside of the plenum. As a result, pressurized air flows outwardly from the interior of the plenum through the holes formed through the upper surface thereof. Usually, the holes formed through the upper surface of the plenum are formed in such a manner that the air flowing from the interior of the plenum is directed generally in a longitudinal direction along the upper surface thereof. Accordingly, articles that are placed upon the upper surface of the plenum are slightly elevated above the upper surface by this flow of pressurized air and urged to move longitudinally along the plenum.
A typical air driven conveyor further includes a top guide for preventing the articles from rising too far above the upper surface of the plenum and, therefore, become prone to tipping over as they are moved longitudinally along the upper surface of the plenum by the flow of pressurized air. The top guide is preferably spaced apart from the upper surface of the plenum by a distance that is only slightly larger than the height of the articles, as defined by the distance between the upper and lower ends thereof. By positioning the top guide at such a distance relative to the upper surface of the plenum, longitudinal movement of the articles along the upper surface of the plenum in the manner described above is not impeded. However, if one of the articles starts to tip over, a portion of the upper end thereof will engage the lower surface of the top guide. Consequently, the articles are effectively prevented from tipping over as they are moved longitudinally along the upper surface of the plenum.
Frequently, a single air driven conveyor is used to support and transport articles having differing sizes. When the size of the articles to be supported and transported is changed, the distance between the top guide and the upper surface of the plenum must usually be changed as well. In the past, the top guide has usually been supported relative to the plenum by a plurality of mounting brackets positioned along the length of the air driven conveyor. As a result, adjustment of the distance between the top guide and the upper surface of the plenum often required that individual adjustments be made to each of the mounting brackets. This usually involved manually loosening a fastener, moving the mounting bracket to its new position, and then tightening the fastener. Such individual adjustment of each of the mounting brackets required large amounts of time and labor, resulting in a significant loss of production capacity. Thus, it would be desirable to provide an improved structure for supporting a top guide relative to a plenum in an air driven conveyor that allows the distance therebetween to be adjusted quickly and easily in order to readily accommodate articles of differing size.